There's no way around it;
scratching is a biological necessity for your cat or kitten. De-clawing, though, can permanently disable your pet, especially if she's an outdoor cat. So what can you do to keep kitty from destroying your new expensive leather couch?
First and foremost, you can't really punish your cat for clawing the furniture, unless you have provided her with an alternative like a scratching post. If your cat has already scratched a piece of furniture, cover it with plastic and she will likely turn to the post instead. When you catch your cat scratching furniture, try squirting her with a water pistol or squirt bottle and use a firm "No." When she scratches her scratching post, reward her with praise and perhaps a treat.
Other tips for foiling your cat's scratching include putting tin foil in places where the cat tries to scratch. The noise and feel of it will scare the cat and make them wary of scratching there again. An alternative would be using double-stick tape. Put large pieces of double-stick tape along the edges of your furniture (where the cat loves to scratch) and the cat will soon avoid those places in frustration. Eventually, you can remove the plastic, foil, or tape and the cat will have already been conditioned
to leave the area alone.
An even better alternative to de-clawing is to keep the cat's claws clipped short either by you or a veterinarian. If you're afraid you'll hurt your cat, most vets will clip your cat's claws for only a nominal fee, usually under $10.
With a little time and patience, your cat will direct his scratching to her post and leave your furniture alone, and you won't have had to cripple her to get her to do it.